Treating device for treating a body part of a patient with a non-thermal plasma

ABSTRACT

The invention relates to a treating device ( 1 ) for treating a body part of a patient with a non-thermal plasma, particularly for sterilizing a hand of a human being, said treating device ( 1 ) comprising a housing ( 2 ) for temporarily receiving the body part within the housing ( 2 ) during the treatment and for applying the plasma to the body part within the housing ( 2 ), and an inlet opening ( 3 ) being arranged in the housing ( 2 ) for introducing the body part through the inlet opening ( 3 ) into the housing ( 2 ).

FIELD OF THE INVENTION

The invention relates to a treating device for treating a body part of apatient with a non-thermal plasma, particularly for sterilizing a handof a human being.

BACKGROUND OF THE INVENTION

The use of non-thermal plasma for the treatment of wounds and especiallyfor the in-vivo sterilization, decontamination or disinfection of woundsis disclosed, for example, in WO 2007/031250 A1, EP 1 925 190 A1 andPCT/EP2008/003568. However, the known devices for plasma treatment aresuitable to only a limited extent for the in-vivo sterilization of ahand of a human being. WO 02/099836 A1 describes an apparatus and methodusing capillary discharge plasma shower for sterilizing and disinfectingarticles. However, also this apparatus is suitable to only a limitedextend for the in-vivo sterilization of a hand, in particular due to theturbulences caused by the shower. Also, the sterilizing and disinfectionability of this device is limited by the copious amounts of reactivegases introduced into the atmosphere—which may lead to health hazards.

SUMMARY OF THE INVENTION

Therefore, it is a general object of the invention to provide a treatingdevice which is suitable for the in-vivo sterilization of a hand of ahuman being.

This object is achieved by a novel treating device according to the mainclaim.

The treating device according to the invention comprises a housing fortemporarily receiving a body part which is to be sterilized within thehousing during the treatment and for applying the non-thermal plasma tothe body part within the housing. Therefore, the treating deviceaccording to the invention is different in nature from conventionaltreating devices in which the object of the treatment (e.g. a hand) islocated outside a plasma applicator so that the plasma applicator mustbe moved along the surface of the object of treatment so that thenon-thermal plasma is applied to the entire surface of the object oftreatment. In other words, in conventional treating devices thenon-thermal plasma is applied to the object of treatment while theinvention provides that the object of treatment (e.g. a hand of a humanbeing) is introduced into the non-thermal plasma so that the object oftreatment is completely surrounded by the non-thermal plasma.

The housing of the treating device according to the invention comprisesan inlet opening for introducing the body part (e.g. a hand of a humanbeing) through the inlet opening into the housing so that the plasmatreatment takes place within the housing.

The treating device according to the invention is particularly suitablefor the in-vivo sterilization of a hand of a human being. However, thetreating device according to the invention can also be used for theplasma treatment of other body parts of a patient, e.g. a foot or aforearm including a hand and preferably further including an elbow of ahuman being. Furthermore, the object of treatment can be anon-biological article like a surgical instrument, an implant, forexample a heart pacemaker, a stent, an artificial joint, or otherdevices to be sterilized.

Further, the treating device according to the invention preferablycomprises an integrated plasma generator for generating the non-thermalplasma within the housing. Therefore, the plasma generator is preferablean integral part of the treating device.

Alternatively, it is possible that the treating device merely comprisesan inlet for introducing the plasma into the housing wherein the plasmais generated outside the housing by a separate plasma generator whichcan be connected with the inlet of the treating device via a hose.

In a preferred embodiment of the invention, the plasma generatorcomprises at least two electrodes and a barrier between the electrodes,so that the plasma is generated between the electrodes by a dielectricbarrier discharge (DBD), which is per se known in the state of the art.Therefore, the barrier between the electrodes preferably consists of anelectrically insulating and/or dielectric material, particularlypolytetraflouroethylene.

Further, the electrodes can be adhered to the barrier on opposite sidesof the barrier.

The at least two electrodes can be provided in a plurality of manners.For example, at least one of the electrodes can be provided as a singlewire. Preferably, at least one of the electrodes is provided spirally,or wound, or flat, or like a cooling coil, or in a meandering manner.

At least one of the electrodes can comprise several perforations, whichare distributed over the electrode. Therefore, the plasma can beproduced within the perforations of the electrode.

Preferably, at least one of the first electrode and the second electrodecomprises a wire-mesh, wherein the afore-mentioned perforations arearranged between individual meshes of the wire-mesh. In other words,each mesh of the wire-mesh forms one of the afore-mentionedperforations. One advantage of such an arrangement is that it isscalable, adaptive and can be customized to any form and shape therebyallowing new applications, e.g. as a wound dressing. Further, such anelectrode arrangement is easy to manufacture and very cost effective.Unlike conventional dielectric barrier devices proposed for plasmamedicine, it does not pass a current through human tissue. Moreover, adouble mesh system can be gas permeable so that a gas flow cantransversely penetrate the electrode arrangement so that it is usefulfor air purification, sterilization and pollution (exhaust) control.

Further, it is possible to arrange several of the afore-mentioneddouble-mesh electrode systems at distances of a few centimeters, whereinthe double-mesh systems are preferably aligned parallel to each other.

In another embodiment, at least one of the first electrode and thesecond electrode comprises a perforated plate in which theafore-mentioned perforations are arranged. For example, the plate can bemade of copper or aluminium wherein the perforations in the plate arepunched out of the plate. Further, it is possible that both electrodesof the electrode arrangement consist of perforated plates, which areseparated by the dielectric barrier.

In yet another embodiment, at least one of the first and secondelectrodes consists of parallel wires or stripes made of an electricallyconductive material.

It should further be noted that in the afore-mentioned embodiments, theperforations are preferably equally distributed over the electrodesurface so that the intensity of the plasma generation is also equallydistributed over the surface of the electrode.

In one embodiment, the first electrode comprises a plate made of anelectrically conductive material, wherein the plate is preferablymassive and does not comprise any perforations. The dielectric barrieris substantially layer-shaped and formed on a surface of the plate. Forexample, the dielectric barrier can have a thickness in the range of0.5-1 mm. In this embodiment, the second electrode comprises either theafore-mentioned wire-mesh or a perforated plate made of an electricallyconductive material. The first electrode formed as a massive plate ispreferably energized with an alternating current with a voltage of 10-20kV and a typical electrical current of 10-30 mA while the secondelectrode formed as a wire-mesh is preferably electrically grounded.

In another embodiment, both the first electrode and the second electrodecomprise a wire-mesh while the dielectric barrier comprises a claddingmade of an electrically insulating and dielectric material surroundingthe wires of at least one of the first electrode and the secondelectrode thereby electrically insulating the first electrode from thesecond electrode. In other words, the electrically insulating anddielectric cladding of the individual wires of the wire-mesh forms thedielectric barrier. The first electrode and the second electrode areattached to each other, preferably by an adhesive bond, so that thewire-meshes of the first and second electrodes are contacting each otherphysically.

In one variant of this embodiment, both the first electrode and thesecond electrode comprise a cladding surrounding the individual wires ofthe wire-mesh thereby forming the dielectric barrier.

In another variant of this embodiment, merely one of the first andsecond electrodes comprises a cladding surrounding the individual wiresof the wire-mesh thereby forming the dielectric barrier. In other words,only one of the first and second electrodes is electrically insulated bya cladding while the other one of the first and second electrodes is notinsulated by a cladding.

It should further be noted that the invention is not restricted toembodiments comprising just two electrodes. For example, it is possibleto provide a third electrode and a further dielectric barrier so thatthere are two dielectric barrier discharge arrangements on both sides ofa centre electrode thereby forming a sandwich-like arrangement.

It has already been mentioned that the electrodes are preferably adheredto each other. It is also possible that the dielectric barrier isadhered to at least one of the first and second electrodes.

Preferably, the electrode arrangement is substantially two-dimensional,flat and deformable so that the shape of the entire electrodearrangement can be adapted to the contour of a body part, which is to betreated.

In another embodiment, the electrode arrangement further comprises acover which is covering the electrode arrangement. The cover can beadapted to increase the local density of the reactive species of theplasma thereby reducing the time needed for sterilization. Further, thecover can be adapted to filter out unused reactive species. It isfurther possible to adapt the cover to effect a better control of theplasma. Finally, the cover can be adapted so that the electrodearrangement can operate under reduced pressure.

The dielectric barrier may consist of an electrically insulating anddielectric material. The dielectric barrier preferably consists ofceramics if high performance is desired. Alternatively, the dielectricbarrier can be made of polytetrafluoroethylene if a lower performance ofthe electrode arrangement is sufficient. Further, the dielectric barriercan be made of polyethylene terephtalate (PET), flexible or rigidglass-ceramic, glas, Mylar®, casting ceramic or oxides. However, themelting point of the dielectric material should preferably be over +100°C.

It should further be noted that the invention is not restricted to anelectrode arrangement as a single component. The invention rathercomprises a complete apparatus for plasma treatment comprising theafore-mentioned electrode arrangement for generating the non-thermalplasma.

Moreover, the electrode(s) is/are preferably connected with a highvoltage generator, which can be arranged separate from the treatingdevice.

The housing of the treating device according to the invention ispreferably box-shaped, whereas there are two of the afore mentionedsandwich-like DBD arrangements within the housing above and below thearea of treatment. Alternatively, the DBD arrangements can be mounted onopposing sides of the housing so that one DBD arrangement is mounted onthe left side of the housing, whereas the other DBD arrangement ismounted on the right side of the housing.

Further, the afore-mentioned sandwich-like DBD arrangement preferablycomprises an outer electric insulation, which is electrically insulatingthe outer electrode of the plasma generator.

Moreover, there is preferably a gap between the outer electricinsulation of the sandwich-like DBD arrangement and the housing, whereinsaid gap allows a gas flow through the gap. This is advantageous sincethe plasma generated in the DBD arrangement must reach the area oftreatment in the centre of the housing so that there must be a gas flowwithin the housing. The gas flow within the housing can be generated bynatural convection due to the different temperatures within the gasvolume. However, it is also possible that the gas circulation within thehousing of the treating device is at least partially caused by a pump,which is preferably arranged separate from the treating device.

Preferably, the treating device includes a waste gas filter. The wastegas filter is arranged and configured to filter waste gas from withinthe housing. For example, a ventilator or another suitable means can beprovided in order to urge (pull/push) the waste gas from within thehousing to the waste gas filter.

It should further be mentioned that the plasma generator is preferablyarranged within the housing so that the plasma is generated within thehousing. Therefore, the treating device according to the invention isdifferent in nature from conventional therapeutic concepts in which thearea of treatment and the area of plasma generation are separated fromeach other. On the contrary, the invention provides that the area oftreatment and the area of plasma generation are at least overlapping oreven identical.

It is well known in the state of the art that plasma generatorsgenerally produce ultraviolet (UV) radiation. In some applications thisUV radiation contributes to the therapeutic effect of the plasmatreatment. However, in other applications, the UV radiation isundesirable. Therefore, the treating device according to the inventionpreferably comprises a radiation shielding being arranged between theplasma generator and the area of treatment within the housing therebyshielding the treated body part against the UV radiation generated bythe plasma generator.

However, the afore-mentioned radiation shielding is preferably gaspermeable so that the plasma can flow through the radiation shieldingand reach the body part which is to be treated. This is important sincethe plasma treatment requires a physical contact between the non-thermalplasma and the body part which is to be treated.

In a preferred embodiment, the radiation shielding comprises severalspaced apart UV blocking shielding elements which are preferably curvedor angled in such a way that there is no intervisibility between theopposing sides of the radiation shielding while the gas flow between theopposing sides of the radiation shielding is not substantiallyconstricted.

The shielding elements are preferably lamellas which are arranged in atleast two adjacent layers wherein the lamellas in the adjacent layersare oppositely angled.

It should further be mentioned that the radiation shielding and/or theshielding elements (e.g. lamellas) preferably consist of or a coatedwith an electrically conductive material so that there is not chargebuild-up on the surface of the shielding elements. The electricallyconductive material of the radiation shielding is preferably metal,particularly copper or tin. It should further be mentioned that theradiation shielding and/or the shielding elements are preferablyelectrically grounded.

In the preferred embodiment of the invention, the electrodes, thebarrier and the outer insulation of the afore mentioned DBD arrangementare preferably flat or layer-shaped. Further, the electrodes cancomprise a wire mesh.

Further, the treating device preferably comprises a spacer which isarranged between the area of treatment on the one hand and the plasmagenerator on the other hand thereby preventing a physical contactbetween the plasma generator and the body part during treatment. Thespacer is preferably substantially flat and/or comprises a wire mesh. Ina preferred embodiment, the spacer is configured and arranged to supportthe object to be treated within the housing.

Moreover, it should be noted that the housing of the novel treatingdevice preferably comprises an outer wall consisting of an electricallyconductive material which is preferably electrically grounded.

The dimensions of the housing are preferably adapted to the size of ahand of a human being so that a patient can introduce his hand throughthe inlet opening into the housing for sterilizing his hand. Therefore,the inlet opening of the housing preferably comprises a height in therange of 2 cm-20 cm and a width in the range of 5 cm-30 cm. It ispreferred that the inlet opening of the housing comprises a width of 10cm and a height of 4 cm.

Further, the housing is preferably sufficiently large for introducing ahand of a human being into the housing so that the entire hand can besterilized within the housing. Therefore, the housing preferablycomprises an inner length in the range of 5 cm-30 cm with a preferredvalue of the inner length of about 11-12 cm. Further, the housingpreferably comprises an inner width in the range of 5 cm-30 cm with apreferred value of the width of about 11-12 cm. Finally, the housingpreferably comprises an inner height in the range of 4 cm-20 cm with apreferred value of the inner height of about 7 cm.

In another preferred embodiment, the dimensions of the housing arepreferably adapted to the size of a forearm including a hand andpreferably further including an elbow of a human being so that a patientcan introduce his forearm including his hand and preferably furtherincluding his elbow through the inlet opening into the housing forsterilizing his forearm including his hand and preferably including hiselbow. Further, the housing is preferably sufficiently large forintroducing a forearm including a hand and preferably further includingan elbow of a human being into the housing so that the entire forearmincluding the hand and preferably further including the elbow can besterilized within the housing.

In another preferred embodiment, the dimensions of the housing arepreferably adapted to the size of a foot of a human being.

It should further be noted that the non-thermal plasma according to theinvention preferably comprises a gas temperature (i.e. the temperatureof the atoms and molecules) below +40° C., when measured on the treatedsurface.

Further, the treating device can include an on/off-switch for switchingthe integrated plasma generator on and off.

Moreover, there can be a light barrier which detects whether an objectof treatment (e.g. a hand) is inserted through the inlet opening intothe housing. The light barrier can be coupled with the plasma generatorso that the plasma generator is switched off if no object is introducedthrough the inlet opening, whereas the plasma generator is switched onif an object of treatment is present within the housing.

In a preferred embodiment, the treating device is configured to providean after glow within the housing for treating the object with thenon-thermal plasma, particularly for the in-vivo sterilization of a handor a forearm including a hand and preferably including an elbow of ahuman being. Within the phase of after glow, the plasma generator doesnot produce plasma. However, plasma within the housing is effective fortreating an object, particularly for the in-vivo sterilization. On theone hand, the use of the after glow can decrease the energy consumptionof the treating device. On the other hand, the use of the after glow canincrease the usage safety of the treating device since no object, inparticular no part of a human being or other sensible objects/devices,is introduced within the housing when the plasma is generated (poweron).

For example, the plasma generator can be switched on and after, forexample, 2 sec. switched off. The plasma generated within the 2 sec.remains effective within the housing for a certain time span afterswitching off for treating an object, particularly for the in-vivosterilization.

Preferably, the treating device includes indicating means for indicatingthe beginning and the end of the after glow.

Preferably, the treating device can include an opening/closing means forclosing the inlet opening during plasma generating and opening the inletopening after plasma generating. In one embodiment, the opening/closingmeans is closed and locked during plasma generating and opens only whenthe plasma generator does not generates plasma.

Further, it is possible to provide a plasma ionization degree sensor fordetecting the ionization degree of the plasma within the housing.

Preferably, the plasma generator, the indicating means and/or theopening/closing means are controlled based on one or more predeterminedtime spans.

However, it is also possible to control the plasma generator, theindicating means and/or the opening/closing means based on theionization degree of the plasma within the housing detected by theplasma ionization degree sensor.

The invention and its particular features and advantages will becomeapparent from the following detailed description considered withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a preferred embodiment of a treatingdevice according to the invention.

FIG. 2 shows another perspective view of the treating device accordingto FIG. 1.

FIG. 3 shows a cross sectional view of the treating device shown inFIGS. 1 and 2.

FIG. 4 shows a schematic view of a plasma generator using dielectricbarrier discharge.

FIG. 5 shows a cross sectional view of the radiation shielding shown inFIG. 4.

FIG. 6 shows a cross sectional view similar to FIG. 3 but also showingthe design of the radiation shielding.

FIG. 7A shows a perspective view of a side plate of the housing of thetreating device.

FIG. 7B shows a perspective view of the isolator of the DBD arrangement.

FIG. 7C shows a perspective view of the front plate of the treatingdevice with an inlet opening.

FIG. 7D shows a perspective view of an intermediate plate of thetreating device.

FIG. 7E shows a perspective view of a rear plate of the treating devicecomprising an opening for cables.

FIG. 7F shows a perspective view of an upper and lower plate of thehousing.

FIG. 7G shows an exemplary embodiment of the electrodes of the aforementioned DBD arrangement.

FIG. 8 shows another embodiment of an electrode arrangement which can beused for plasma generation instead of the DBD arrangement.

FIG. 9A shows a perspective view of a preferred embodiment of a DBDelectrode arrangement comprising a plate as a first electrode and awire-mesh as a second electrode.

FIG. 9B shows a sectional view of the electrode arrangement according toFIG. 9A.

FIG. 10 shows a perspective view of an electrode arrangement comprisingtwo wire-meshs.

FIG. 11 shows a perspective view of a junction of the wires of severalwire-meshs.

FIG. 12 shows a perspective view of a junction of two insulated wires.

FIG. 13 shows a modification of the electrode arrangement according toFIG. 10 additionally comprising a cover.

FIG. 14 shows a cross-sectional view of a sandwich-like DBD electrodearrangement comprising three electrodes.

FIG. 15 shows a sectional view of a modification of the embodimentaccording to FIGS. 9A and 9B, wherein a wire-mesh is embedded into thedielectric barrier.

FIGS. 16A and 16B are schematic views illustrating different uses of anafter glow.

DETAILED DESCRIPTION OF THE DRAWINGS

The drawings illustrate a preferred embodiment of a treating device 1for the in-vivo sterilization of a hand or a forearm including a handand preferably further including an elbow of a human being by means of anon-thermal plasma.

The treating device 1 comprises a box-shaped housing 2 with an inletopening 3 at the front side of the housing 2 wherein the dimensions ofthe inlet opening 3 are adapted to the size of a hand of a human beingso that a patient can introduce his hand through the inlet opening 3into the housing 2 of the treating device 1. Further, the dimensions ofthe entire housing 2 are adapted to the size of a hand of a human beingso that the entire hand can be placed within the housing 2 for a plasmatreatment. In this embodiment, the housing 2 comprises a length of 11.5cm, a width of 11.4 cm and a height of 7 cm. Further, the inlet opening3 comprises a width of 10 cm and a height of 4 cm.

Further, the treating device 1 comprises an opening 4 at its rearsurface opposite the inlet opening 3 while the opening 4 serves foraccommodating cables or the like. However, the rear opening 4 is coveredby an insulator 5 consisting of polytetraflouroethylene.

Further, the treating device 1 comprises an integrated plasma generatorwhich generates a non-thermal plasma for the in-vivo sterilization.

The plasma generator comprises two substantially flat dielectric barrierdischarge (DBD) arrangements 6, 7. The DBD arrangement 6 is arrangedwithin the housing 2 above the area of treatment as shown in FIG. 3,while the DBD arrangement 7 is arranged within the housing 2 below thearea of treatment.

The design of the DBD arrangements 6, 7 is schematically shown in FIG.4. Each of the DBD arrangements 6, 7 comprises a barrier 8 sandwichedbetween two electrodes 9, 10 which are adhered to the top and bottomsides of the barrier 8 which consists of polytetraflouroethylene.

Further, the DBD arrangement 6 comprises an outer insulator 11 and aradiation shielding 12 facing to the area of treatment within thehousing 2 so that the radiation shielding 12 prevents that the hand ofthe patient within the housing 2 is affected by any ultravioletradiation generated by the DBD arrangements 6, 7.

FIG. 5 shows a cross sectional view of the radiation shielding 12 alongline A-A in FIG. 4. The radiation shielding 12 comprises two adjacentlayers 13, 14 of parallel metallic lamellas 15, 16. The lamellas 15 inthe upper layer 13 of the radiation shielding 12 are oppositionallyangled with regard to the lamellas 16 in the lower layer 14 of theradiation shielding 12. Therefore, there is no intervisibility betweenthe opposing sides of the radiation shielding 12 so that no ultravioletradiation is transmitted through the radiation shielding 12. In otherwords, the radiation shielding 12 blocks any ultraviolet radiationgenerated by the DBD arrangements 6, 7.

Further, the treating device 1 comprises two spacers 17, 18 for the DBDarrangements 6, 7, wherein the spacers 17, 18 avoid a physical contactbetween the hand and the DBD arrangements 6, 8. In this embodiment, thespacers 17, 18 each consist of a wire mesh.

FIGS. 7A-7G show different views of the parts of the afore mentionedtreating device while the views are self explanatory so that no furtherexplanation is necessary.

FIG. 8 shows another embodiment of an electrode arrangement which can beused instead of the afore-mentioned DBD arrangements 6, 7.

The electrode arrangement comprises a copper plate 19, a teflon plate 20and a wire mesh 21 made of an electrically conductive material. Thecopper plate 19 and the wire-mesh 21 are adhered to opposing sides ofthe teflon plate 20.

Further, the wire mesh 21 is electrically grounded, whereas the copperplate 19 is connected with a high voltage source generating ahigh-voltage of U=18 kV_(pp) and a frequency of f=12.5 kHz.

FIGS. 9A and 9B show another preferred embodiment of a DBD electrodearrangement 1A for generating a non-thermal plasma. The electrodearrangement 1A comprises a plate-shaped electrode 2A made of anelectrically conductive material, e.g. copper or aluminium. Theplate-shaped electrode 2A has a thickness in the range of 0.5-1 mm.

Further, the electrode arrangement 1A comprises a dielectric barrier 3Amade of polytetrafluoroethylene, wherein the material of the dielectricbarrier 3A is applied to the lower surface of the plate-shaped electrode2A.

Moreover, the electrode arrangement 1A comprises a further electrode 4Aformed by a wire-mesh which is adhered to the dielectric barrier 3A onthe side opposite the electrode 2A.

The electrode 4A is electrically grounded while the other electrode 2Ais electrically connected to a high voltage generator 5A which isapplying an alternating current signal to the electrode 2A with afrequency of f=12.5 kHz and a peak-to-peak-voltage of HV=18 kV_(pp).Therefore, the high voltage generator 5A triggers a dielectric dischargewherein the plasma is generated in the meshes of the mesh-shapedelectrode 4A.

FIG. 10 shows another embodiment of a two-dimensional electrodearrangement 11A similar to the electrode arrangement 1A shown in FIGS.9A and 9B.

However, the electrode arrangement 11A comprises two mesh-shapedelectrodes 12A, 13A, wherein the individual wires of at least one of theelectrodes 12A, 13A are surrounded by a cladding made of an electricallyinsulating and dielectric material forming a dielectric barrier betweenthe electrodes 11A, 12A.

The electrode 13A is electrically grounded while the other electrode 12Ais connected to a high-voltage generator 14A triggering a dielectricbarrier discharge in the electrode arrangement 11A wherein the plasma isgenerated in the meshes of the electrodes 12A, 13A.

It should further be noted that the electrode arrangement 11A isflexible so that the shape of the electrode arrangement 11A can beadapted to any desired shape.

FIG. 11 shows a junction between individual wires 15A, 16A, 17A ofadjacent mesh-shaped electrodes. In this embodiment, the wire 16A issurrounded by a cladding 18A made of an electrically insulating anddielectric material thereby forming the dielectric barrier. The otherwires 15A, 17A are not insulated.

FIG. 12 shows another embodiment of a junction of wires 19A, 20A ofadjacent mesh-shaped electrodes. In this embodiment both the wire 19Aand the wire 20A is surrounded by a cladding 21A, 22A made of anelectrically insulating and dielectric material.

FIG. 13 shows a modification of the electrode arrangement shown in FIG.10 so that reference is made to the above description relating to FIG.10.

One characteristic feature of this embodiment is that the electrodearrangement 11A additionally comprises a cover 23A. The cover can havedifferent purposes, e.g. increasing the local density of reactivespecies, reducing the time for sterilization, filtering out unusedreactive species, effecting a better control over the plasma oroperating under reduced pressure.

FIG. 14 shows another embodiment of an electrode arrangement 28Asuitable for generating a non-thermal plasma. The electrode arrangement28A comprises a centre electrode 29A formed by a massive plate made ofcopper.

Further, the electrode arrangement 28A comprises two flat dielectricbarriers 30A, 31A each consisting of a flat plate made ofpolytetrafluoroethylene, wherein the dielectric barriers 30A, 31A areattached to opposing sides of the centre electrode 29A.

Further, the electrode arrangement 28A comprises two mesh-shaped outerelectrodes 32A, 33A which are attached to the outer sides of thedielectric barriers 30A, 31A.

FIG. 15 shows a modification of the electrode arrangement shown in FIGS.9A and 9B so that reference is made to the above description relating toFIGS. 9A and 9B. Further, the same reference numerals are used forcorresponding parts and details.

One characteristic feature of the electrode arrangement 1A according toFIG. 15 is that the electrode 4A is embedded into the dielectric barrier3A. There is a distance d1=1 mm between the wire-mesh of the electrode4A and the lower surface of the electrode 2A. Further, there is adistance d2=0.1 mm between the wire-mesh of the electrode 4A and theouter surface of the dielectric barrier 3A. It is essential that thedistance d1 is greater than the distance d2. However, if it is desiredto have a discharge on one side only, the embedded electrode 4A must beembedded more deeply than the distance d1 between the electrodes 2A, 4A.

If a flexible electrode arrangement 1A is desired, both electrodes 2A,4A are made of a flexible wire-mesh or parallel wires having a distanceof approximately 1 cm, wherein the dielectric barrier 3A can be made ofa flexible material, e.g. silicone rubber.

The outer electrodes 32A, 33A are electrically grounded while the centreelectrode 29A is electrically connected to a high-voltage generator.

FIGS. 16A and 16B are schematic views describing different uses of anafter glow.

In FIG. 16A, the plasma generator is switched on at time t1 andpreferably automatically switched off after a predetermined time at timet2. Thus, the plasma generator generates plasma within time t1 and timet2. Although the plasma generator is switched off between time t2(beginning of the after glow) and time t3 (end of after glow), theplasma generated between time t1 and time t2 and contained within thehousing 2 is effective for treating an object, particularly for thein-vivo sterilization for a hand and/or a forearm of a human being. Thetime span between time t2 and time t3 can thus be referred to as afterglow.

After time t3, the plasma within the housing is no longer effective fortreating an object, particularly not effective for the in-vivosterilization.

The treating device can include an indicating means, for exampleacoustic and/or visual means, for example one or more lamps forindicating particularly times t1, t2 and t3. For example, one lamp canlight yellow between time t1 and time t2 indicating that an objectshould or must not be introduced into the housing. Another lamp canlight green between time t2 and time t3 indicating that the treatingdevice is ready for treating/sterilizing. Still another lamp can lightred after time t3 indicating that the plasma within the housing is nolonger effective for treating/sterilizing.

The treating device can further include an opening/closing meansarranged and configured to close the inlet opening 3 when the plasmagenerator generates plasma (e.g. between time t1 and time t2) forpreventing an object, for example a hand, to be introduced into thehousing and to open the inlet opening 3 when the plasma generator doesnot produce plasma (e.g. during time t2 and time t3). Although thedevice is safe even when the plasma is generated (due to the groundedelectrode configuration), the use of the after glow may further increaseusage safety. For example, the use of the after glow can have advantagesin particular with regard to wet objects and metallic objects (e.g.rings, watches, bracelets).

It is also possible to provide a plasma ionization degree sensor fordetecting the plasma effectiveness/ionization degree within the housing2 and to control the plasma generator, the opening/closing means and/orthe indicating means in response to the values detected by the plasmaionization degree sensor. However, it is also possible to control theplasma generator, the indicating means and/or the opening/closing meansby one or more predetermined time spans. The one or more time spans canbe preset by the manufacturer of the treating device and/or individuallydefinable by a user, for example a physician or a nurse.

It is further possible to maintain the treating device in a “stand bymode” as schematically shown in FIG. 16B. In FIG. 16B, the plasmagenerator is initially switched on at time t. The plasma generator isautomatically switched off at time t″, automatically switched on at timet′, automatically switched off at time t″ and so on. Thus, afterinitially switching on the treating device (for example in the morningand switched off in the evening), the plasma effectiveness/ionizationdegree within the housing 2 is kept at a sufficient (predetermined)degree for treating/sterilizing. With other words, the treating deviceis after switching on permanently effective for treating an object,particularly for the in-vivo sterilization. The embodiment shown in FIG.16B can be used with the indicating means, the opening/closing meansand/or the plasma ionization degree sensor according to FIG. 16A.

Although the invention has been described with reference to theparticular arrangement of parts, features and the like, these are notintended to exhaust all possible arrangements of features, and indeedmany other modifications and variations will be ascertainable to thoseof skill in the art.

1. A treating device for treating an object with a non-thermal plasma,for the in-vivo sterilization of a hand of a human being, comprising a)a housing for temporarily receiving the object within the housing duringthe treatment and for applying the plasma to the object within thehousing, and b) an inlet opening being arranged in the housing forintroducing the object through the inlet opening into the housing. 2.The treating device according to claim 1, further comprising a) anintegrated plasma generator for generating the non-thermal plasma withinthe housing, or b) an inlet for introducing the plasma into the housingwherein the plasma is generated outside the housing.
 3. The treatingdevice according to claim 2, wherein the plasma generator comprises atleast two electrodes and a barrier between the electrodes, so that theplasma is generated between the electrodes by a dielectric barrierdischarge.
 4. The treating device according to claim 2, wherein thebarrier between the electrodes consists of an electrically insulatingand/or dielectric material, particularly polytetrafluoroethylene.
 5. Thetreating device according to claim 4, wherein the electrode is adheredto the barrier.
 6. The treating device according to claim 5, wherein atleast one of the electrodes is connected with a high voltage generator.7. The treating device according to claim 6, further comprising an outerelectric insulation which is electrically insulating the outer electrodeof the plasma generator.
 8. The treating device according to claim 7,further comprising a gap between the outer electric insulation and thehousing for allowing a gas flow through the gap.
 9. The treating deviceaccording to claim 8, wherein the plasma generator is arranged withinthe housing.
 10. The treating device according to claim 9, furthercomprising a radiation shielding being arranged between the plasmagenerator and the object within the housing thereby so as to shield theobject against ultraviolet radiation generated by the plasma generator.11. The treating device according to claim 10, wherein the radiationshielding is gas permeable so that the plasma can flow through theradiation shielding and reach the object.
 12. The treating deviceaccording to claim 10 or 11, wherein a) the radiation shieldingcomprises several spaced apart shielding elements, and b) the shieldingelements are curved or angled so that there is no intervisibilitybetween opposing sides of the radiation shielding.
 13. The treatingdevice according to claim 12, wherein a) the shielding elements arelamellas and b) the lamellas are arranged in at least two adjacentlayers, and c) the lamellas in the adjacent layers are oppositionallyangled.
 14. The treating device according to claim 12, wherein a) theradiation shielding and/or the shielding elements consist of or arecoated with an electrically conductive material, and b) the electricallyconductive material is metal, comprising copper or tin, and c) theradiation shielding and/or the shielding elements are electricallygrounded.
 15. The treating device according to claim 7, wherein theelectrodes and/or the barrier and/or the outer insulation and/or theradiation shielding is substantially flat and/or layer-shaped.
 16. Thetreating device according to claim 15, wherein the electrodes and/or thebarrier and/or the outer insulation comprise a wire mesh.
 17. Thetreating device according to claim 1, further comprising a spacer forpreventing a physical contact between the plasma generator and theobject within the housing.
 18. The treating device according to claim17, wherein the spacer is substantially flat.
 19. The treating deviceaccording to claim 17, wherein the spacer comprises a wire mesh.
 20. Thetreating device according to claim 17, wherein the spacer is configuredand arranged to support the object within the housing.
 21. The treatingdevice according to claim 1, wherein a) the housing comprises an outerwall consisting of an electrically conductive material, or b) the outerwall of the housing is electrically grounded.
 22. The treating deviceaccording to claim 21, wherein a) the inlet opening in the housing issuitable for introducing a hand or a forearm including a hand andpreferably further including an elbow of a human being through the inletopening into the housing, and b) the inlet opening in the housingcomprises a height which is greater than 2 cm and smaller than 30 cm,and c) the inlet opening in the housing comprises a width, which isgreater than 5 cm and smaller than 65 cm, and/or d) the housing isadapted for introducing a hand or a forearm including a hand andpreferably further including an elbow of a human being into the housing,and e) the housing comprises an inner length, which is greater than 5 cmand smaller than 65 cm, and f) the housing comprises an inner width,which is greater than 5 cm and smaller than 65 cm, and g) the housingcomprises an inner height, which is greater than 4 cm and smaller than30 cm.
 23. The treating device according to claim 1, wherein thetreating device is configured to provide an after glow within thehousing.
 24. The treating device according to claim 23, furthercomprising indicating means for indicating the beginning and the end ofthe after glow.
 25. The treating device according claim 24, furthercomprising opening/closing means for closing the inlet opening when theplasma generator generates plasma and opening the inlet opening when theplasma generator does not generate plasma.
 26. The treating deviceaccording claim 25, further comprising a plasma ionization degree sensorconfigured for detecting the ionization degree of the plasma within thehousing.
 27. The treating device according claim 26, wherein at leastone of the plasma generator, the indicating means and theopening/closing means is controlled based on one or more predeterminedand/or individually definable time spans.
 28. The treating deviceaccording claim 26, wherein at least one of the plasma generator, theindicating means and the opening/closing means is controlled based onthe ionization degree of the plasma within the housing as detected by aplasma ionization degree sensor.
 29. A method of using a treating devicefor sterilizing an object of treatment, the method comprising: providinga housing having an inlet opening; introducing the object through theinlet opening into the housing; and applying a non-thermal plasma to theobject of treatment within the housing, wherein the object of treatmentis selected from the group consisting of: a) an extremity of a humanbeing, comprising a hand or a foot, b) a surgical instrument, c) animplant, comprising a heart pacemaker, a stent, an artificial joint, andd) other devices to be sterilised.
 30. The method according to claim 29,wherein the object of treatment comprises an extremity of a human being.